Request Tracing

Gerrit supports on-demand tracing of single requests that results in
additional logs with debug information that are written to the
error_log. The logs that correspond to a traced request are
associated with a unique trace ID. This trace ID is returned with the
response and can be used by an administrator to find the matching log
entries.

How tracing is enabled and how the trace ID is returned depends on the
request type:

REST API: For REST calls tracing can be enabled by setting the
trace request parameter or the X-Gerrit-Trace header, the trace
ID is returned as X-Gerrit-Trace header. More information about
this can be found in the Request Tracing
section of the REST API documentation.

SSH API: For SSH calls tracing can be enabled by setting the
--trace option. More information about this can be found in
the Trace section of the
SSH command documentation.

Git: For Git pushes tracing can be enabled by setting the
trace push option, the trace ID is returned in the command output.
More information about this can be found in
the Trace section of the
upload documentation. Tracing for Git requests
other than Git push is not supported.

When request tracing is enabled it is possible to provide an ID that
should be used as trace ID. If a trace ID is not provided a trace ID is
automatically generated. The trace ID must be provided to the support
team so that they can find the trace.

When doing traces it is recommended to specify the ID of the issue
that is being investigated as trace ID so that the traces of the issue
can be found more easily. When the issue ID is used as trace ID there
is no need to find the generated trace ID and report it in the issue.

Since tracing consumes additional server resources tracing should only
be enabled for single requests if there is a concrete need for
debugging. In particular bots should never enable tracing for all their
requests by default.

Find log entries for a trace ID

If tracing is enabled all log messages that correspond to the traced
request have a TRACE_ID tag set, e.g.: